Abstract: An improved process for the continuous discharge from a first separation zone of a first heavy fraction comprising insoluble coal products and solvent in a coal deashing process utilizing solvents at elevated pressures and temperatures near the critical temperature of the solvent. The continuous discharge of the insoluble coal products in a dry, powdery form, is achieved by monitoring the temperature level of the solvent and insoluble coal products within a transfer conduit after withdrawal and pressure reduction from the first separation zone operating pressure, at a temperature below about 550 degrees F.

Abstract: An improved coal deashing process wherein soluble dissolved coal present in the ash concentrate product stream from a critical solvent deashing process can be separated and recovered from the ash concentrate by at least two alternate processing systems.In one such system, the ash concentrate (containing dissolved and undissolved coal) is admixed with a suitable organic solubilizing solvent to obtain partial redissolution, at elevated temperature and at pressures of atmospheric and above, and thereafter subjecting said mixture to a separation treatment. The liquid product thus separated, containing substantially all of the dissolved coal and only a minor amount of mineral ash, thereafter is recycled to the initial coal dissolution step to thereby provide a portion of the initial solvent necessary for preparation of the coal feed.

Abstract: An improved coal deashing process wherein coal is mixed with a first dissolving solvent, solubilized and flashed to provide a prepared mixture, and the prepared mixture is mixed with a second dissolving solvent to produce a feed mixture. The insoluble coal products produced are separated from the feed mixture as a first heavy fraction in a first separation zone and the soluble coal products are recovered as a second heavy fraction from a second separation zone. The second dissolving solvent is recovered from the first heavy fraction and the second heavy fraction for recycling to aid in the production of the feed mixture. The first dissolving solvent is recovered from the first and the second heavy fractions and recycled to aid in solubilization of the coal.

Abstract: An improved coal deashing process wherein coal is mixed with a first dissolving solvent, heated, solubilized and flashed to provide a prepared mixture. The flashing is effected at a temperature below about 650.degree. F. to increase the amount of the first dissolving solvent in the prepared mixture. The prepared mixture then is mixed with a second dissolving solvent to produce a feed mixture which is subjected to two or more successive phase separations. Insoluble coal products present are separated from the feed mixture in a first separation zone and the soluble coal products are recovered from the first and the second dissolving solvents in a second separation zone. The second dissolving solvent is recovered from the first and the second heavy fractions and the second light fraction for recycling to aid in producing the feed mixture. The first dissolving solvent is recovered from the first and second flash zones.